Note K - Stock-based Compensation Plans (Tables)

12 Months Ended

Apr. 30, 2022

Notes Tables

Stock Option Plan Comparison [Table Text Block]

	Restated Option Plan
Minimum exercise price as a percentage of fair market value at date of grant	100%
Last expiration date for outstanding options	May 1, 2031
Shares available for grant at April 30, 2022	215,000

Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	April 30, 2022		April 30, 2021		April 30, 2020
Expected terms (years)		5.5		5.5		5.5
Risk-free interest rate		0.86%		0.36%		1.75%
Volatility		51%		50%		39%
Dividend yield		-		-		-

Share-Based Payment Arrangement, Option, Activity [Table Text Block]

	Number			Exercise		Proceeds			Weighted Average
	of			Price		on			Exercise Price per
	Options			per Share		Exercise			Share
						(in thousands)
Outstanding at April 30, 2019		565,500				$	26,087		$	46.13
Granted		225,000		99.0505 to109.06.06			24,287			107.95
Exercised		(121,250	)	22.8787 to53.02.02			(4,517	)		37.25
Cancelled		(1,500	)		$ 53.02		(80	)		53.02
Outstanding at April 30, 2020		667,750				$	45,777		$	68.55
Granted		30,000			$ 65.95		30			65.95
Exercised		(131,350	)	24.6969 to99.05.05			(6,730	)		51.24
Outstanding at April 30, 2021		566,400				$	39,077		$	72.43
Granted		30,000			$ 150.83		30			150.83
Exercised		(94,000	)	26.3737 to150.83.83			(6,276	)		66.76
Cancelled		(1,000	)		$ 41.86		(42	)	$	41.86
Outstanding at April 30, 2022		501,400				$	32,789

Schedule of Share-based Compensation, Stock Options, Exercises [Table Text Block]

	Years Ended April 30,
(Dollars in thousands)	2022		2021		2020
Options Exercised		94,000		131,350		121,250
Cash Received from Options Exercised	$	591	$	5,120	$	2,928
Intrinsic Value of Options Exercised	$	7,124	$	7,894	$	7,580

Share-Based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block]

	Number of Shares			Weighted Average Grant Date Fair Value
Unvested shares at April 30, 2019		180,500		$	46.16
Shares granted		12,328			102.03
Shares vested		(7,000	)		52.10
Shares cancelled		(1,000	)		37.07
Unvested shares at April 30, 2020		184,828		$	49.71
Shares granted		7,690			98.43
Shares vested		-			-
Shares cancelled		(500	)		35.00
Unvested shares at April 30, 2021		192,018		$	51.70
Shares granted		11,287			121.17
Shares vested		(6,500	)		39.14
Shares cancelled		(15,691	)		59.99
Unvested shares at April 30, 2022		181,114		$	55.76